Didn't happen every attempt, but over our 15 wipes to him it at least cost us 3 wipes. I don't know if it's exactly as detailed in this thread but we would reveal a red beast and it would blow up half way through, even though the person piloting the red beam is in the same location that it revealed the beast.

Happens on normal too. Found an add with the red beam and then the add just vanished and blew up. Just to clarify... the beam was not moved off the add but the add vanished and did the damage to the raid as if the beam had been moved off it. A few seconds later the add reappeared so we could kill it or it just despawned (not sure which happened) and the light specrtum phase ended. Never saw it happen before 5.3.

We have Durumu on farm but last night we couldn't kill it. This bug kept wiping us on every attempt, since the red add exploding is pretty much a one-shot for most of our raid at that point (hc mode). The bug would occur at different points during the encounter, but always at least once (including on one occasion at 20% or so boss health which is fucking frustrating).